This invention relates to the art of automatic fastening machines, and more particularly to a new and improved apparatus and method for applying sealant to fasteners prior to installation by such machines.
One area of use of the present invention is in automatic drilling and riveting machines where a drill forms a hole in a workpiece and then a fastener, such as a rivet, is inserted in the hole and upset in the workpiece. However, before the inserting and upsetting operations it often is necessary to apply a liquid sealant to the fastener which sets-up after the upsetting operation to enhance the fluid-tight nature of the joint between the rivet and workpiece. An example of the foregoing is in riveting aircraft wings wherein fuel storage regions are defined within the wings.
In the design of apparatus to perform such sealant application, several important objectives should be met. Any sealant application method and apparatus should be compatible with, preferably a part of, the fastener installation operation. Furthermore, variations in size and types of fasteners should be accommodated. In addition, due to the nature of the sealant material, maintenance and replacement of the apparatus or its components should be convenient.